EEA standard re-use policy: unless otherwise indicated, re-use of content on the EEA website for commercial or non-commercial purposes is permitted free of charge, provided that the source is acknowledged (http://www.eea.europa.eu/legal/copyright). Copyright holder: European Environment Agency (EEA).
Aragonite is a form of calcium carbonate used by organisms such as corals, molluscs and some plankton species to build up skeletal structures and shells. Aragonite saturation levels go down as the ocean water acidifies. A value below 100% indicates undersaturation, meaning that aragonite structures would dissolve. Lowering values imply that it becomes increasingly difficult for the mentioned organisms to survive and grow.